[gdb/python] Handle empty PYTHONDONTWRITEBYTECODE

When using PYTHONDONTWRITEBYTECODE with an empty string we get:
...
$ PYTHONDONTWRITEBYTECODE= gdb -q -batch -ex "show python dont-write-bytecode"
Python's dont-write-bytecode setting is auto (currently on).
...

This is incorrect, it should be off.

The actual setting is correct, that was already fixed in commit 24d2cbc42cc
("set/show python dont-write-bytecode fixes"), in function
python_write_bytecode.

Fix this by:
- factoring out new function env_python_dont_write_bytecode out of
  python_write_bytecode, and
- using it in show_python_dont_write_bytecode.

Tested on x86_64-linux, using test-case gdb.python/py-startup-opt.exp and:
- PYTHONDONTWRITEBYTECODE=
- PYTHONDONTWRITEBYTECODE=1
- unset PYTHONDONTWRITEBYTECODE

Approved-By: Tom Tromey <tom@tromey.com>
PR python/32389
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32389

diff --git a/gdb/python/python.c b/gdb/python/python.c
index d754908bdd50b0b2a99ae361a282a44ac0b2056e..8d61b9c6f015e4f40578abb59ddb1e596fc636ae 100644 (file)
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -2141,6 +2141,17 @@ set_python_ignore_environment (const char *args, int from_tty,
    not write `.pyc' files on import of a module.  */
 static enum auto_boolean python_dont_write_bytecode = AUTO_BOOLEAN_AUTO;
 
+
+/* Return true if environment variable PYTHONDONTWRITEBYTECODE is set to a
+   non-empty string.  */
+
+static bool
+env_python_dont_write_bytecode ()
+{
+  const char *envvar = getenv ("PYTHONDONTWRITEBYTECODE");
+  return envvar != nullptr && envvar[0] != '\0';
+}
+
 /* Implement 'show python dont-write-bytecode'.  */
 
 static void
@@ -2150,8 +2161,10 @@ show_python_dont_write_bytecode (struct ui_file *file, int from_tty,
   if (python_dont_write_bytecode == AUTO_BOOLEAN_AUTO)
     {
       const char *auto_string
-       = (python_ignore_environment
-          || getenv ("PYTHONDONTWRITEBYTECODE") == nullptr) ? "off" : "on";
+       = ((python_ignore_environment
+           || !env_python_dont_write_bytecode ())
+          ? "off"
+          : "on");
 
       gdb_printf (file,
                  _("Python's dont-write-bytecode setting is %s (currently %s).\n"),
@@ -2177,10 +2190,7 @@ python_write_bytecode ()
       if (python_ignore_environment)
        wbc = 1;
       else
-       {
-         const char *pdwbc = getenv ("PYTHONDONTWRITEBYTECODE");
-         wbc = (pdwbc == nullptr || pdwbc[0] == '\0') ? 1 : 0;
-       }
+       wbc = env_python_dont_write_bytecode () ? 0 : 1;
     }
   else
     wbc = python_dont_write_bytecode == AUTO_BOOLEAN_TRUE ? 0 : 1;

diff --git a/gdb/testsuite/gdb.python/py-startup-opt.exp b/gdb/testsuite/gdb.python/py-startup-opt.exp
index 014aff5725a62421b954fd6cd0b6443c660ffb49..df35a37865828993decf0e6b3d94f0f3d65b3ef3 100644 (file)
--- a/gdb/testsuite/gdb.python/py-startup-opt.exp
+++ b/gdb/testsuite/gdb.python/py-startup-opt.exp
@@ -93,6 +93,14 @@ proc test_python_settings { exp_state } {
            "else:" "" \
            "  print (\"${attr} is off\")" "" \
            "end" "${attr} is ${answer}"
+
+       if { $attr == "dont_write_bytecode" && $exp_state == "off" } {
+           set setting dont-write-bytecode
+           set show_setting \
+               "Python's $setting setting is auto (currently $answer)."
+           gdb_test "show python $setting" \
+               [string_to_regexp $show_setting]
+       }
     }
 
     gdb_exit